There are a number of great Instructables on LED grids out there.  This is a low cost version - not quite as polished, but easy to make.

This project uses a couple of sheets of foam core, a fluorescent fixture cover from the local home store, a cut up strip of WS2812b LEDs, and an Arduino.  All fairly inexpensive if you know where to get them (info below).

  • LEDs - this project uses 25 LEDs, and there are a few choices here.  For this one, a strip of WS2812b LEDs was used.  There were 30 per meter in the strip I ordered, which makes soldering easier since they are farther apart.  The 60/meter strips would also work.  The 144/meter would not work since they only have one set of solder pads between each LED to allow them to be so close, and for this project, we are soldering wires between them all and need soldering pads on both sides.  You could also use the WS2801 based strands, and those are typically pre-wired, making the project even easier.  The other Instructables cover those pretty well, so this one will not go into more detail on those.  Use non-waterproof or silicone jacketed (the jacket can be slid or cut off) strips.  Avoid the epoxy waterproofed ones since you will need to clean that off of each end of each LED - doable, but unnecessary work if you order the other kind.
  • Foam Core - 2 sheets, 20"x30", like these, though that link is 5x more than you need.
  • Plastic cover - this is from the local home store and is used to cover fluorescent bulb fixtures.  It's called an acrylic lighting panel, and the style is cracked ice.  There are other possibilities here - the main thing is there is enough frosting to diffuse the LED light.  Since the lighting panels are about 24"x 48", you can make two of these projects with one of them.
  • Wire - each LED will have wires to connect to the next one - three wires between each.  Hobby servo wire is nice to use since it's already three wires and color coded nicely.
  • An Arduino Uno will do.  Clone Arduinos are are available for about $10 each - a key for the low cost goal of this project.  There are also smaller versions of Arduinos that would also work well for this project in that same price range.  Older Arduinos will work fine too.
  • Recommended - a power jack to supply 5 volts to the system.  You can use the Arduino power and regulator if most of the LEDs are not on at the same time, but if they will all be on, the external 5 volts supply will avoid overheating the Arduino regulator.  This jac will match your power supply - for me, it was a 2.1mm ID, 5.5 mm OD panel mount jack.

Step 1: Making the Grid

Cut (12) 2" strips off the 20" end of one piece of foam core.  Cut the second piece of foam core into a 20"x20" piece for the back.

On the strips, cut a 1/4" wide, 1" + 1/16" deep slot on the end, and at 4", 8", 12", and 16" (see the pictures).  They are all cut the same and will fit into each other.  This is easy if you have a band saw, but you can use a hand saw or an X-Acto knife and some patience.

On 4 of them, cut a notch on the tops to run the wires.  On 4 others, cut notches on the bottom left of two of them and the bottom right of the other two.  The remaining 4 are the sides and need no notches (the pictures show each of the 4 types).

Don't glue them all down yet since you will need to run the wires!  I used hot melt glue.  I glued the sides in first - added the strips in the one direction that is captured by the sides, but did not glue them yet.  Then I noticed you can remove them by flexing them slightly, and removed them while gluing down the LEDs.  Once all the LEDS are set, you can add glue as needed, but you may not actually need much more - depends how rigid you want it to be.

Cut the plastic lighting panel to 20"x20".  It is very brittle, so the special scoring tool they sell may help - otherwise a box cutter may work, but be sure to have the panel on a flat surface.

<p>no code :(</p>
<p>The video is mostly just showing the strandtest example from the Neopixel library from Adafruit. You can get that here: <a href="https://github.com/adafruit/Adafruit_NeoPixel" rel="nofollow">https://github.com/adafruit/Adafruit_NeoPixel</a></p><p>There are other libraries like FastLED that are good too: <a href="https://github.com/FastLED/FastLED" rel="nofollow">https://github.com/FastLED/FastLED</a> - many samples there.</p><p>I may do another Instructable on making it controllable over the web - similar to my LED Tower one: https://www.instructables.com/id/Web-Controlled-Wifi-LED-Tower/</p><p>Hope that helps!</p>
<p>could you make a video of you making the LED Grid</p>
Good idea! I am not sure when I will make another one, but if I do, I could capture a build video.
I'm curious, did you cut the LEDs from the strip because the spacing was wrong for the project? Could they be used as supplied and the grid size adjusted?
Yes - they were cut and wired so there would be one LED per grid element. The WS2801 strands are pre-wired - slightly different, but very popular for this kind of project. If you wanted to run a full strip of the WS2811/WS2812 LEDs across each row, say, you could probably make it work. You would still want to wire each row to the next. You could either use a much finer grid to get one LED per cell, or have a few LEDs per cell. These LEDS are very bright, so that would be an intense display!
Thanks. I'd more than likely adjust the size of the project to the spacing. I love soldering, but my love has limits!
Awesome idea! Finally a project that does not use a 3D printer. I like the idea of using the foam board. I often thought of that. Simple and easy. I would cover the wires with some white tape.
Thanks. I think covering the wires is not needed - I had a few loops sticking up that you can see in the pictures, but I hot-melt glued them down, and they do not show up now. Hiding the Arduino is trickier - I tried covering it with paper, but that makes a shadow - it would either need to be below the LED, outside the box, or one of tiny compatible boards. It is not a huge obstruction, though.
hey we should combine this with my software https://www.instructables.com/id/arduino-powered-light-show/
Cool project! I have seen a number of ones where people put a lot of lights outside their house, and then manually sequence a whole show to a specific song. This is one that I saw recently: https://plus.google.com/+GregScull/posts/4aDiZ6AdfGQ?cfem=1
Could you make something like this for a beat machine?
You'd need to add touch sensors for each grid element - I have definitely seen other projects like this - don't have a URL handy, but if I come across any, I will post them.
What a great effect for such simple materials. :D
Thanks! Working on a holiday program now...

About This Instructable




Bio: A Maker since childhood with all the classic symptoms, a robot builder, and an Internet software CTO by day.
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